Cylinder head cracked between #2 and #3
 

Hello everyone,


on Monday I started to remove the cylinder head because I still had problems with an overheating engine under >50% load along with foaming coolant. Retorquing the head didn't change anything, so I suspected a damaged head gasket.
Upon removal I found that the head gasket seemed fine. I couldn't find any cracks in the block either, though I still need to check the intake and exhaust ports tomorrow.
I did, however, find 2 small cracks in the cylinder head, between #2 and #3, shown in the picture below. The seemingly excessive rust in the combustion chambers is from a combination of the lighting when taking the picture as well as having cleaned the combustion chambers and having used sulfamic acid to clean the water passages from as much rust and scale as possible followed by flushing the head with water. The rust-ish color on the mating surface seems to be copper residue, either from copper spray or the old copper head gasket.


My question is do the cracks cause problems or can I use this head?
I did not notice any coolant loss around the head stud, the stud isn't heavily corroded either. From my understanding these two cracks shouldn't cause any problems, but I still like to check with people who have more experience in this field as this is the first cylinder head I've removed.


I'll use a copper head gasket (Snyders A-6051-C), should I use copper spray or another sealant or install the gasket dry? How about a thin layer of Hylomar M on both sides of the gasket?



Have a nice day,


Daniel

Re: Cylinder head cracked between #2 and #3
 

For me, the Best brand graphite gaskets with the copper spray gasket sealer works the best. Correct me if I am wrong, but it looks like a stock head. You will be very happy with a higher compression head, such as Snyder's 5.5 to 1 or 6.0 to 1. Stock heads are easy to come by so if you want to keep using a stock head then I would scrap that one and look around for a good quality used stock one.

Is the block damaged where the head sits? Sometimes there can be scratches or worn areas. Check to make sure the block and the head are flat. Any depressions can be filled with JB Weld after cleaning the part with acetone. The cured adhesive can be sanded flat with some fine grit sand paper wrapped around a flat file.

Do not use a wire brush to clean the block as the wires that break off can get stuck between the piston and the cylinder and cause scratches.

I don't see where the cracks could be causing over heating. The foam coolant is not going to conduct heat very well. I would guess it was the coolant and perhaps some other problem with the cooling system, such as a defective or clogged radiator. Try switching antifreeze brand or try just water (for a test, not permanent). If air was being pumped into the coolant from the cracks then that could have caused the foaming. But the gasket should have sealed off the cracks from the combustion chambers.

Re: Cylinder head cracked between #2 and #3
 

I'll have to check tomorrow if there's damage in that area, didn't see any while cleaning the block though.
I already removed built up carbon and cleaned the surface with acetone, so any crack should be visible. Wouldn't want to use a steel wire brush as I fear that would scratch the surface. I did use a brass brush to carefully clean the valves from carbon buildup, but I also used a vacuum cleaner to suck up any carbon and dirt while cleaning. The cleanup was surprisingly easy for a change, nothing usually is on that car. :P


It is a stock head as far as I can tell, yeah. I know that higher compression heads are nice to have, but the price for a new head + shipping to Germany is not really worth it to upgrade in my opinion. We're talking at least 700 bucks until it's at my door, shipping costs over the ocean suck.

Even stock heads are not easy to find over here, spare parts sadly are a lot harder to find than in the USA and the things you do find tend to be worn out.



I'm fine with the performance of the stock engine if I can use full throttle to accelerate after reassembly and can cruise at 45 mph without the coolant foaming up as I avoid driving on the highway and the main roads anyway.




EDIT: I installed a new 10 fpi radiator (Snyders A-8005-AX) last year, so I can probably rule out a fauly rad.
I did shake up the anti freeze in the container I drained it into and there was immediate foaming, so maybe it really is anti freeze that only works properly in a pressurized system?
After reassembly I'll run water for some time until the head gasket has fully seated. Should the problem be gone I'll look for another anti freeze or run anti corrosion additives only.

Re: Cylinder head cracked between #2 and #3
 

My head is cracked like that, made a temporary repair over 40 years ago.
I drilled and tapped for a small brass screw , tightened it till it bottoms out, cut it off a little above the surface tapped on it with a hammer to set it, then filed it flat.
Used the factory wrench to tighten it. Checked that the nuts were tight the 2 mornings after before driving , not touched since, no seeping. —— so for me it hasn’t caused any problems having that crack.

Re: Cylinder head cracked between #2 and #3
 

No problem. Use Copper spray ,tacky to install with proper torque procedures! Copper gasket.Model A Ford Garage ~ Brumfield Cylinder Head Gasket Instructionss follow these instructions to the letter and you will never have a problem.

Re: Cylinder head cracked between #2 and #3
 

That's a very common place to crack. Have it surfaced and go for it.

Re: Cylinder head cracked between #2 and #3
 

Labor costs being what they are these days, I bet you can find a decent used head, or go for a high compression head. The correct gasket is a big deal.

Re: Cylinder head cracked between #2 and #3
 

Update:


Totally forgot to give feedback on the question about the block. I cleaned it properly and could find no damage to the block anywhere. There were 5 studs that I did not manage to get out, but as the threads were fine I just let them in the block. Didn't want to break one off and deal with having to remove it.
The 9 studs that I did get out were replaced with new ones, coated with proper anti-seize on the block side.

Meanwhile I properly flushed the block and checked the head on a flat granite block. The head's a bit warped. I decided to try my luck and install it without having it machined. After coating both sides of the head gasket with a small film of Hylomar M the head + gasket were assembled and the bolts torqued in steps in the correct order.
Later I'll assemble the radiator and distributor and do a first warmup of the engine.

Is there a recommended temperature to tighten the bolts again or is just lukewarm fine?


Should the head be too distorted for the gasket to properly seal off I'll just dismantle it again. Now that all bolts have been removed and the head isn't backed on anymore that should go much faster than the first time. :D

EDIT:
While cleaning up the head I also removed two disc-like shaped *things* from inside the head around cylinder 2 and 3 on the outlet side. They had a diameter of around 2 inches and a thickness of maybe 1/4 inch. Only god himself knows what these things were, my guess is either severely dried up water pump grease or remains from an earlier repair of the head. Either way it certainly did not help coolant flow in the middle of the head, where temperature was consistently 5 - 10 °C higher than at cyl. 1 or 4. Maybe that was the main problem all along? We'll see...

Re: Cylinder head cracked between #2 and #3
 

cold -follow the link in #5 to the letter!